This module exports exactly the same API as System.Posix, except
that all file paths and environment strings are represented by
ByteString instead of String. The System.Posix API
implicitly translates all file paths and environment strings using
the locale encoding, whereas this version of the API does no
encoding or decoding and works directly in terms of raw bytes.

Note that if you do need to interpret file paths or environment
strings as text, then some Unicode encoding or decoding should be
applied first.